Turn brightness off auto and turn it as low as you can while still comfortable.
Update that amazon mp3 bloatware with the market, the new version doesn't autostart. Check other apps that update in the background and either turn them off or make the checks every few hours.
Take advantage of wifi calling!! If you are in an office all day make sure it's on, will save tons of battery.
I'd you don't need it, turn off 3g when not planning to use data for a while.
Welcome to the horrible battery world of modern smartphones...